The invention relates to a motor vehicle having a high-voltage source.
High-voltage sources that provide the required electrical energy are required for operating electric machines for electric vehicles and hybrid vehicles. High-voltage hereinafter refers to voltages greater than 60 V which pose a considerable health risk for operators and service personnel upon contact. Currently, typical onboard voltages are approximately 400 V; however, the use of even higher voltages is desirable to limit the currents flowing in the onboard high-voltage system while operating a motor vehicle.
When servicing such vehicle, it must be ensured that the high-voltage source is safely disconnected from the onboard high-voltage system to prevent health risks for the service personnel. Electric vehicles therefore typically have a so-called service connector, wherein removal of this connector cause the high-voltage onboard power supply system to be physically interrupted, thus preventing any current flow. Likewise, it is known to interrupt the onboard high-voltage power supply system by using control devices which separate the high-voltage source from the onboard high-voltage system via one or more contactors.
A signal light is typically provided to indicate to the service personnel that the high-voltage source is disconnected; the signal light turns off when a voltage is no longer present in the onboard high-voltage power supply. However, such signal lamp does not represent a foolproof indication of the zero-voltage state of the onboard high-voltage power supply, since the zero-voltage state cannot be distinguished from a defective signal light.
WO 99/50131 A1 discloses a battery having a disconnectable output; in addition, the battery includes a display device, which emits a signal when switching between the live state and the zero-voltage state, and back. Also, such a display would not enable a reliable detection of the zero-voltage state, but only a change of the state.
It is therefore an object of the present invention to provide a motor vehicle of the aforedescribed type which allows a reliable indication of the zero-voltage state of the onboard high-voltage power supply.